import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';

/* class Square extends React.Component {
  render() {
    return (
      <button className="square" onClick={() => this.props.onClick()}>
        {this.props.value}
      </button>
    );
  }
} */

// 函数定义组件
function Square(props) {
	return (
		<button className="square" onClick={props.onClick}>
        {props.value}
      </button>
	)
}

//判断赢家
function calculateWinner(squares) {
	const lines = [
    [0, 1, 2],
    [3, 4, 5],
    [6, 7, 8],
    [0, 3, 6],
    [1, 4, 7],
    [2, 5, 8],
    [0, 4, 8],
    [2, 4, 6],
	];
	
	for (let i = 0; i < lines.length; i++) {
		const [a, b, c] = lines[i];
		if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
			return squares[a];
		}
	}
	return null;
}

class Board extends React.Component {
	constructor() {
		super();
		this.state = {
			squares : Array(9).fill(null),
			xIsNext : true
		}
	}
  renderSquare(i) {
    return <Square value={this.state.squares[i]} onClick={() => this.handleClick(i)} />;
  }

	handleClick(i) {
		const squares = this.state.squares.slice();
		// 继续完善游戏规则，我们在 handleClick 里添加当前方格内已经落子/有一方获胜就就无法继续
		if (calculateWinner(squares) || squares[i]) {
      return;
    }
    squares[i] = this.state.xIsNext ? 'X' : 'O';
    this.setState({
			squares: squares,
			xIsNext: !this.state.xIsNext
		});
	}
	
  render() {
    // const status = 'Next player: ' + (this.state.xIsNext ? 'X' : 'O');

		const winner = calculateWinner(this.state.squares);
    let status;
    if (winner) {
      status = 'Winner: ' + winner;
    } else {
      status = 'Next player: ' + (this.state.xIsNext ? 'X' : 'O');
		}
		
    return (
      <div>
        <div className="status">{status}</div>
        <div className="board-row">
          {this.renderSquare(0)}
          {this.renderSquare(1)}
          {this.renderSquare(2)}
        </div>
        <div className="board-row">
          {this.renderSquare(3)}
          {this.renderSquare(4)}
          {this.renderSquare(5)}
        </div>
        <div className="board-row">
          {this.renderSquare(6)}
          {this.renderSquare(7)}
          {this.renderSquare(8)}
        </div>
      </div>
    );
  }
}

class Game extends React.Component {
  render() {
    return (
      <div className="game">
        <div className="game-board">
          <Board />
        </div>
        <div className="game-info">
          <div>{/* status */}</div>
          <ol>{/* TODO */}</ol>
        </div>
      </div>
    );
  }
}

// ========================================

ReactDOM.render(
  <Game />,
  document.getElementById('root')
);
